WO2006000332A1

WO2006000332A1 - Device and method for stabilising a motor vehicle

Info

Publication number: WO2006000332A1
Application number: PCT/EP2005/006451
Authority: WO
Inventors: Markus Raab
Original assignee: Daimlerchrysler Ag
Priority date: 2004-06-25
Filing date: 2005-06-16
Publication date: 2006-01-05
Also published as: JP2008503389A; US20080033612A1; DE102004048531A1

Abstract

The invention relates to a device and to a method for stabilising a motor vehicle, comprising a detection device (10) which determines an actual value of a lateral dynamics variable describing the lateral dynamics of the motor vehicle, and an evaluation device (11) which determines a desired value for the lateral dynamics variable and defines a threshold value which is determined according to a predetermined stability condition, if the desired value of the lateral dynamics exceeds the determined threshold value. The evaluation device (11), which is used to influence the longitudinal and/or lateral dynamics of the motor vehicle provided for the motor vehicle units (12) according to a comparison between the determined actual value and the determined and, optionally, defined desired value of the lateral dynamic variable, is controlled in such a manner that the driving stability of the motor vehicle is increased. The lateral dynamics variable has a tilting angle variable which describes a tilting angle of the motor vehicle, and/or a slip angle variable, which describes a slip-angle occurring on a motor vehicle wheel.

Description

Device and method for stabilizing a vehicle

The invention relates to a device and a method for stabilizing a vehicle, having a detection device which is provided for determining an actual value of the transverse dynamics of the vehicle describing transverse dynamics variable, and having an evaluation unit which determines a desired value for the transverse dynamics variable and limits it to a limit value determined as a function of a predefined stability condition, if it is found that the setpoint value of the transverse dynamic quantity exceeds the determined limit value, wherein the evaluation unit controls vehicle units provided for influencing the longitudinal and / or lateral dynamics of the vehicle as a function of a comparison between the determined actual value and the determined and, if appropriate, limited setpoint value of the transverse dynamics variable are controlled in such a way that the driving stability of the vehicle is increased.

Such a stabilization system for a vehicle is apparent from the document DE 198 30 189 Al. The vehicle has a device for yaw moment control, which controls the yaw rate of the vehicle in a known way by wheel-selective interventions in Radbremsein¬ the vehicle to a driver default dependent setpoint, the setpoint to avoid tipping over the vehicle on ei¬ NEN physically meaningful value is limited. Since only an indirect physical relationship exists between the yaw rate used for the yaw moment control and the occurrence of a tilt or spin tendency of the vehicle, inaccuracies in the assessment of the actual stability state of the vehicle inevitably result. Under unfavorable conditions, this can lead to an inadequate execution of the wheel-selective interventions in the wheel brake devices of the vehicle, which is inappropriate for the actual stability state.

It is therefore an object of the present invention to develop a device or a method of the type mentioned at the outset in such a way that an implementation of vehicle-stabilizing measures appropriate to the actual stability state of the vehicle is ensured.

This object is achieved by a device or a method according to the features of patent claim 1 and patent claim 12.

The device for stabilizing a vehicle further comprises, in addition to a detection device which is provided for determining an actual value of a transverse dynamics parameter describing the lateral dynamics of the vehicle, an evaluation unit which determines a desired value for the transverse dynamics variable and determines it to a condition dependent on a predetermined stability condition Limits limited if it appears that the setpoint value of the transverse dynamics quantity exceeds the determined Grenz¬ value magnitude, wherein the evaluation unit provided for influencing the longitudinal and / or lateral dynamics of the vehicle provided Fahrzeugaggregate depending on a comparison between the determined actual value and the ermittel¬ th and possibly limited setpoint of Querdynamik¬ size controls such that the driving stability of the vehicle is increased. According to the invention, the lateral dynamics quantity comprises a tilt angle variable which describes a tilt angle of the vehicle and / or a slip angle variable which indicates one describes a slip angle occurring in a vehicle wheel. The skew angle here indicates that angular deviation which occurs due to wheel side forces between the actual rolling direction of the vehicle wheel and its rim plane.

Since the tilt angle and / or the slip angle is physically directly related to the occurrence of a tilting and / or slipping tendency of the vehicle, it is largely possible to avoid inaccuracies in the assessment of the stability state of the vehicle, so that the actual stability state is obtained adequate implementation of the vehicle stabilizing measures can be ensured.

Advantageous embodiments of the device according to the invention will become apparent from the dependent claims.

Advantageously, the tilt angle size describes the tilt angle itself and / or the temporal behavior of the tilting angle, so that a tendency to tilt of the vehicle can be reliably detected by evaluating the tilt angle variable. The temporal behavior of the tilt angle results beispielswei¬ se by temporal derivative of the tilt angle. In particular, the tilt angle represents a rotation of the vehicle about an axis of rotation oriented in the vehicle longitudinal direction, which may also be a rotation of the vehicle about an axis of rotation oriented in the vehicle transverse direction or a superimposition of the two aforementioned rotations.

Furthermore, it is advantageous if the slip angle size describes the skew angle occurring at a front wheel axle of the vehicle and / or the slip angle occurring at a rear wheel axle of the vehicle. Since the skew angle occurring at the front wheel axle and / or the slip angle occurring at the rear wheel axle have a physiologically direct connection to the occurrence of an overlay angle. or Untersteuerungstendenz the vehicle is, a spin tendency of the vehicle can be detected particularly reliable by evaluating the skew angle.

The latter is particularly the case when the skew angle size describes a skew angle difference between the skew angle occurring at the front wheel axle of the vehicle and the skew angle occurring at the rear wheel axle of the vehicle, because due to magnitude and sign the skew angle difference directly affects the occurrence an oversteer or Untersteuerungstendenz and thus a tendency to spin of the vehicle can be closed.

In order to be able to reliably counteract a tilting and / or spinning tendency of the vehicle, there is the possibility that the evaluation unit for carrying out vehicle-stabilizing measures as a function of the comparison between the actual value and the desired value of the transverse dynamics variable sets a target value of a yawing moment variable for increasing the driving stability on the vehicle. which describes a yaw moment acting on the vehicle. The vehicle gensets are then controlled in such a way that an actual value of the yaw moment variable corresponding to the determined setpoint value is set on the vehicle.

The vehicle assemblies include in particular Radbremseinrich¬ lines, which are provided for braking vehicle wheels, the control of Radbremseinrichtungen er¬ for increasing the driving stability of the vehicle by radselektive specification to be generated braking torque and / or braking forces er¬ follows. Since such braking torques and / or braking forces can be generated in the case of pressure-operated wheel brake devices with high accuracy and with a slight time delay, a particularly precise and responsive implementation of the vehicle-stabilizing measures is made possible. The vehicle-stabilizing measures can be carried out particularly precisely if, when the wheel-selective specification of the braking torques and / or braking forces to be generated, a possibly present driver-side braking torque and / or braking force requirement is also taken into account. The braking torque and / or braking force request can be derived, for example, from a driver-side actuation of a brake operating element provided for controlling the wheel brake devices.

In addition to the described interventions in the wheel brake devices of the vehicle, vehicle-stabilizing inputs into the drive and / or the steering of the vehicle can also be undertaken, for example by suitable reduction of the drive torque and / or in the form of steering corrections counteract an occurring tilt and / or spin tendency of the vehicle.

Advantageously, the actual value and / or the desired value and / or the limit value of the transverse dynamics variable are determined on the basis of an input variable which describes the instantaneous state of motion of the vehicle. In this case, the determination of the actual value and / or the desired value and / or the limit value of the transverse dynamics variable can take place under real-time conditions, so that the occurrence of a tilting and / or swerving tendency of the vehicle can be directly reacted, and can be largely avoided time delays in the implementation of vehicle stabilizing measures. If no great demands are placed on the accuracy of the limitation of the setpoint value, it is possible to save the computational effort otherwise required for its determination by fixed specification of the limit value.

In order to be able to describe the current state of motion of the vehicle as accurately as possible, the state of motion variable is a longitudinal speed variable which describes a longitudinal speed of the vehicle, and / or a lateral velocity variable describing a lateral velocity of the vehicle, and / or a lateral acceleration variable describing a lateral acceleration acting on the vehicle, and / or a buoyancy variable describing the lateral angle of the vehicle, and / or a yaw rate describing the yaw rate of the vehicle, and / or a wheel steering angle variable describing a wheel steering angle set on steerable vehicle wheels, and / or spring travel amounts describing spring deflection occurring at wheel spring devices of the vehicle, and / or a roll rate variable; which describes the roll rate of the vehicle, and / or about a center of gravity position that describes the position of the vehicle's center of gravity, and / or a Haftrei¬ advertising size that describes a occurring between vehicle wheels and Fahr¬ track surface stiction.

The device according to the invention or the method according to the invention will be explained in more detail below with reference to the attached drawings. Showing:

Fig. 1 is a schematically illustrated embodiment of

device according to the invention,

Fig. 2 shows an embodiment of the Verfah¬ invention

in the form of a flow chart.

1 shows a schematically illustrated embodiment of the device for stabilizing a vehicle.

The device, which is a fahr¬ based on a Riccati regulator stability controller for performing acts zeugstabilisierender measures, in addition to having Er¬ detection means 10, which _is a mikgröße the transverse dynamics of the vehicle described Querdyna¬ for detecting an actual value of x provided , furthermore an evaluation unit 11, which is in communication with the detection device 10, setting a target value x _so n determined for the lateral dynamics variable, and in response to a subsequent comparison between the determined actual value _is x and the target value determined x _soll of the lateral dynamics variable for influencing the longitudinal and / or transverse dynamics of the vehicle provided Fahrzeugaggre¬ gate 12 so controls in that the driving stability of the vehicle is increased.

The transverse dynamics variable includes a tilt angle variable φ, which describes a tilt angle φ of the vehicle, and / or a slip angle variable a, which corresponds to a slip angle a appearing on a vehicle wheel. describes. In this case, the skew angle α indicates the angular deviation that occurs due to wheel side forces between the actual rolling direction of the vehicle wheel and its rim plane. In the present exemplary embodiment, the skew angle variable ot describes the skew angle α _h occurring at a rear wheel axle of the vehicle, that is to say

oc = (α _h ) (ii:

Furthermore, for the Kippwinkelgröße φ, which describes both the tilt angle φ itself and its temporal behavior, a relationship of the shape

be valid. Overall, for the actual value x _is the Querdynamik¬ size so

By way of example, the tilt angle variable φ represents a rotation of the vehicle about a rotational axis oriented in the vehicle longitudinal direction, ie about the roll axis of the vehicle, which alternatively also involves a rotation about an axis of rotation oriented in the vehicle transverse direction or an overlap of the two above may be called rotations. The determination of the tilt angle variable φ is based on spring travel values d _{i (i = 1} ... ₄₎ which describe spring deflection occurring on the vehicle's wheel suspension devices the track width of the vehicle and the spatial distance of the tilting center of the vehicle from the road surface are taken into account.

For detecting the spring travel dimensions d _{iii = 1.} , ₄ spring travel sensors 10a are provided which register the spring travel auftre¬ to the Radfedereinrichtungen compression paths and generate corresponding Federweg¬ signals which are the Äuswerteeinheit 11 supplied to determine the Kippwinkelgröße φ. In this case, the determination can be carried out using a suitable observer concept in which not only the spring travel variables d _{i (1 = 1} " _.4 but also input parameters describing the vehicle dynamics behavior of the vehicle can enter, so that a particularly high determination accuracy can be achieved.

For the sake of simplicity, a tilting angle sensor can also be present instead of the spring travel sensors 10a, by means of which the tilting angle φ of the vehicle and / or its temporal behavior for determining the tilting angle variable φ can be detected directly. The temporal behavior of the tilt angle φ is then obtained by temporal derivation of the detected tilt angle cp. In particular, since the tilt angle quantity φ represents a rotation of the vehicle about the roll axis oriented in the longitudinal direction of the vehicle, it is possible in particular for the tilt angle sensor to detect a roll rate variable which describes the roll rate of the vehicle, whereby the roll rate size is integrated by offset-corrected integration the tilt angle φ can be gained by the axis of rotation oriented in the vehicle longitudinal direction.

Furthermore, the evaluation unit 11 determines the skew angle variable α on the basis of a longitudinal velocity variable V ₁ , which describes the longitudinal velocity of the vehicle, and / or a float angle variable β, which describes the float angle of the vehicle, and / or a yaw rate ψ, which the Yaw rate of the vehicle describes, and / or a Rad¬ steering angle δ, which describes the wheel steered ein¬ on steerable vehicle wheels, wherein a connection of the shape

is taken as a basis. The size l _h here represents the distance between the center of gravity of the vehicle and the rear wheel axis of the vehicle in the vehicle longitudinal direction.

The determination of the longitudinal speed variable V ₁ takes place in the evaluation unit 11 by evaluation of wheel speed signals which are provided by wheel speed sensors 10 b, which detect the wheel speeds occurring at vehicle wheels. Parallel to this, the evaluation unit 11 determines the yaw rate quantity ψ on the basis of a yaw rate signal provided by a yaw rate sensor 10c for detecting the yaw rate of the vehicle, and the wheel steering angle δ on the basis of a wheel steering angle signal from one for detecting the wheel steering angle provided Rad¬ steering angle sensor 10d is available determined.

The flotation angle variable β is then obtained from the determined longitudinal velocity variable V ₁ and a determined transverse velocity variable v _q , which describes a lateral velocity of the vehicle v, ß = tg (1.5a) v ^■

wherein the determination of the lateral velocity variable v _{q is} effected by offset-corrected integration of a lateral acceleration variable a _q , which describes a transverse control acting on the vehicle. The lateral acceleration quantity a _q is determined here by the evaluation unit 11 on the basis of a transverse acceleration signal which is provided by a transverse acceleration sensor 10 e which detects the lateral acceleration acting on the vehicle. Alternatively, the lateral velocity variable v _{q can} also be measured directly or can be determined using an observer model, in which, for example, the wheel steering angle variable δ and the longitudinal velocity variable V ₁ are received.

As a rule, the buoyancy angle ß has small values, so that equation (1.5a) approximates to a good approximation

If an essentially negligible slip between the vehicle tires and the road surface is assumed, the float angle variable β can be simply expressed by the determined wheel steering angle variable δ (so-called Ackermann relationship),

ß «δ- ^, (1.5c)

wherein the size 1 represents the vehicle longitudinal direction distance between the front wheel axle and the rear wheel axle of the vehicle. To realize the stability controller, the time derivative of the actual value x of the lateral dynamics variable _is considered in the following, so that equation (1.3) in

passes. The determination of the vector components occurring in equation (1.6) is based on an actual value z _is a state variable which fully and uniquely characterizes the instantaneous state of motion of the vehicle. The actual value z _is the state variable resulting from the swing angle ß and / or the yaw rate ψ and / or the tilt angle φ. For the time derivative of the actual value z _, the state variable,

^z is - ψ (1.7) Φ

then follows

I ₂ (β, ψ, φ, φ, δ, M _Bfij , Zist =: i.8) Φ

wherein the quantities I ₁₁ I ₂ and f ₄ for determining the actual value zi _St the state variable provided functional relationships in the example according to the Schwimmwinkelgröße ß and / or the yaw rate ψ and / or the Kippwinkelgröße φ and / or the Radlenkwinkelgröße δ and / or a yawing moment variable to be set on the vehicle to increase driving stability M _Brψ , which writes a yawing moment acting on the vehicle, is received.

The actual value x _is the transverse dynamic quantity then results from the actual value z _is the state variable by executing a state transformation of the shape

Xist = Φ (Zist (1.9)

so that equation (1.6) in

respectively .

x is -: i. ii)

passes. The form of the actual value xi _{St of} the transverse dynamic quantity given by equation (1.11) considerably facilitates the realization of the stability controller. This is especially the case when Equation (1.11) leads to an initially affine representation of the shape

φ φ ^x is - f ₃ (φ, φ, φ, δ, δ) + g ₃ (φ, φ, φ, δ, δ) M _{B (ψ} (1.12) f _t (φ, φ, φ, δ, Ö) + g ₄ (φ, φ, φ, δ, δ) M _{B; ψ j}

is converted, in which adjust to implement the fahr¬ vehicle stabilizing measures on the vehicle Yaw momentum quantities M _{B (ψ} yield as easily determinable coefficients of the functional relationships g ₃ and g ₄ .

In the present _exemplary embodiment, equation (1.12) yields a total of two desired values M ₅₀₁₁ ≡ M ^ _j1 to be set on the vehicle; for the yaw moment size,

-f ₃ (φ, φ, φ, δ, δ) + - φ _s + q ₂ , _φ (φ _s -φ) + q _{1 / (p} (φ _s -φ) + q _o , _φ (φ _s - φ) M 's "oll ... • g ₃ (φ, φ, φ, δ, δ) (1.13a)

- f ₄ (φ, φ, φ, δ, δ) + - ^ α _h , _s + q _o , _a (α _h , _s -α _h ^1J should be g ₃ (φ, φ, φ, δ, δ) ( 1.13b)

The coefficients of the characteristic equations (1.13a) and (1.13b) q _{0 / (p,} q _{1 ((p,} q _2, φ and q _o, _α filters Regelungsverstär¬ kung factors is that allow, the control behavior of the stability of the regulator as desired In addition to the control characteristic of the vehicle assemblies 12 used for carrying out the vehicle-stabilizing measures, the vehicle dynamics properties of the respective vehicle or vehicle type (passenger cars, lorries, buses, etc.) must be taken into consideration.

The incoming into equations (1.13a) and (1.13b) Soll¬ value X i ₁ _5O the transverse dynamics variable,

is determined by the evaluation unit 11 on the basis of the Längsgeschwin¬ digkeitsgröße V ₁ and / or the Schwimmwinkelgröße ß and / or the yaw rate ψ and / or the Radlenkwinkelgröße δ and / or the lateral acceleration magnitude a _q and / or a center of gravity position size s _sp , which describes the position of the Fahrzeugschwer¬ point determined. The determination of the desired value x _so ii of the transverse dynamic quantity thus takes place using a functional relationship of the shape

x AOII _so ≡X ii (vi, a _{q /} ß, t, δ _f s _ap) (1.15)

which reproduces the dynamic driving behavior of the respective vehicle or vehicle type.

The center of gravity position size s _sp is obtained by evaluating the temporal behavior of the spring deflection paths occurring at the wheel spring devices, that is to say by temporal evaluation of the spring travel variables

In order to avoid overturning or skidding of the vehicle, the evaluation unit 11 limits the setpoint value x _so n of the transverse dynamic quantity that enters the equations (1.13a) and (1.13b) to a limit value x limit prescribed as a function of a predetermined stability _condition , if it appears that the setpoint value x _{soU of} the transverse dynamic quantity exceeds the limit value x _{limit in terms of} magnitude. The determination of the threshold x _cross the lateral dynamics variable on the basis of the longitudinal speed variable V ₁ and / or the transverse acceleration size a _q and / or the Radlenkwinkelgröße δ and / or the center of gravity size s _sp and / or a static friction size μ _r, the one between the vehicle wheels and the Fahrbahnober¬ area occurring stiction describes. The static friction variable μ _r is determined in the evaluation unit 11 on the basis of a roadway condition signal which is provided by a roadway condition sensor 10 f provided for detecting the roadway surface condition. Alternatively, the limit value x _{limit of} the transverse dynamic quantity can also be fixed. The roadway condition sensor 10f, like the spring travel sensors 10a, the wheel speed sensors 10b, the yaw rate sensor 10c, the wheel steering angle sensor 10d and the lateral acceleration sensor 10e, is part of the detection device 10.

The quantities determined by means of the detection device 10 from the evaluation unit 11 in this case form the input variables of the stability controller. Since these describe the instantaneous state of motion of the vehicle, the desired value M _{soll of} the yaw moment variable can be determined under real-time conditions, so that it is possible to react directly to the occurrence of a tilt or spin tendency of the vehicle. For carrying out the vehicle-stabilizing measures, the stability controller uses in each case the magnitude-larger of the two setpoints M _g011 , M ₃₀₁₁ given by the equations (1.13a) and (1.13b),

M ₅₀₁₁ = MaX [IM ^ ₀₁₁ I, IM _s ^α _oll I], (1. 16,)

Alternatively, a corresponding weighting of the setpoint values M _g011 , M " _O11 by means of suitable weighting factors λ _φ , X ₀ , is conceivable,

M _so ii ⁼ λ _(p M ^ _oll + λ _α M _s ^κ _oll . (1. 17)

This approach has the advantage that the occurrence of both a tilt and a tendency to spin of the vehicle can be counteracted simultaneously.

The evaluation unit 11 controls the vehicle units 12 then in dependence of the process performed in the equations (1.13a) and (1.13b) comparison between the determined actual value _x and value the detected and possibly limited Soll¬ x _to the transverse dynamics variable, q _o, _φ ( φ _s -φ), qi, _φ (φ _s -φ), q ₂ , _φ (φ _s ~ φ ^" ) ^{un (} d qo, oι (oc _h , _s -α _h ) such that ei ^' n the ermit ^¬ telten setpoint M ₃₀₁₁ M corresponding actual value _is the Giermo¬ management size to the vehicle is set. In this manner, both avoided a tilting tendency leading to a roll or lateral tipping as well as a tendency to spin of the vehicle leading to a lurching or spinning or at least largely suppressed.

The vehicle units 12 are, for example, wheel brake devices 12a... 12d provided for braking vehicle wheels, which can be actuated by a control device 12e on the part of the evaluation unit 11. The control device 12e is an arrangement of electromechanical pressure valves in the case of pressure-driven wheel brake devices 12a. The control of the wheel braking device 12a... 12d takes place in accordance with the ascertained setpoint value M _{soll of} the yaw moment variable by means of wheel-selective predetermination of braking torques and / or braking forces to be generated.

In order to avoid inaccuracies in the implementation of the vehicle-stabilizing measures, the evaluation unit 11 takes into account the braking-torque and / or braking force requirement, if present on the driver side, during the wheel-selective specification of the braking torques and / or braking forces to be generated. The braking torque and / or braking force request results from a driver-side actuation of a brake operating element 13 provided for actuating the wheel brake devices 12a to 12d, which is a conventional brake pedal, for example.

In order to detect the driver-side actuation of the brake operating element 13, a brake operating element sensor 14 is provided which registers a deflection m caused by the driver on the brake control element 13 and converts it into a corresponding deflection signal, which the evaluation unit 11 then determines to determine the brake torque and / or o¬ the braking force request is supplied.

In the following, alternative embodiments of the stability regulator are to be presented. According to an alternative embodiment of the device according to the invention, the slip angle variable α describes both the slip angle α _h occurring at the rear wheel axle of the vehicle and the slip angle α _v occurring at a front wheel axle of the vehicle

Of. oc = (2.1) α _h

In this case, for the Kippwinkelgröße φ a Zusammen¬ hang the shape

HI (2.2)

be valid. Overall, for the actual value x _lst, the transverse dynamic quantity follows

The evaluation unit 11 determines the slip angle α based on the longitudinal velocity V ₁ and / or the Schwimmwinkelgröße ß and / or the yaw rate ψ and / or the Radlenkwinkelgröße δ, where relationships of the shape

ψ-1, α _v = -δ + β + (2.4) v

and

Ψ -1. α _h = β- (2.5) V _l

be based on. The size l _v or l _h hereby sets the distance present in the vehicle longitudinal direction the vehicle center of gravity and the front wheel axle or the rear wheel axle of the vehicle.

After execution of the state transformation described in connection with the previous embodiment

results in an equation (1.12) analogous input-affine representation of the shape

<P f ₂ (φ, φ, α _v , α _h , δ, δ; X ist - (2.8) f ₃ (cp, φ, α _v , α _h , δ, δ) + g ₃ (φ, φ, α _v , α _h , δ, δ) MB, ψ f ₄ (φ, φ, α _v , α _h , δ, δ) + g ₄ (<p, φ, α _v , α _h , δ, δ) MB, ψ y

It can be shown that equation (2.8) then yields only a single setpoint M _soll ≡ M _Br φ for the yawing moment variable to be set on the vehicle, so that a prioritization or weighting according to equation (1.16) or (1.17), as in the case of several Setpoints M _{should be} necessary in principle, can be omitted. In this way, a further improvement with regard to the reliability in the implementation of the vehicle-stabilizing measures can be achieved.

According to a further alternative embodiment of the device according to the invention, the slip angle variable α describes the skew angle difference Δα = α _v -α _h between the skew angle α _v occurring at the front wheel axle of the vehicle and the slip angle α _h occurring at the rear wheel axle of the vehicle. so

α = (Δα). (3.1) In this case, for the Kippwinkelgröße φ a Zusammen¬ hang the shape

be valid. For the actual value x _lst the transverse dynamics quantity follows

wherein after execution of the state transformation

Xist = Φ (z _is ) (3.4)

now an initial affine representation of the figure

φ ^X is - f ₃ (φ, φ, φ, Δα, δ, δ) + g ₃ (φ, φ, φ, Δα, δ, 5) M _B ^ (3.5) f ₄ (φ, φ, φ, Δα, δ, δ) + g ₄ (φ, φ, φ, La, δ, δ) M _{B # ϊ j}

results. Like equation (2.6), equation (3.5) provides only a single setpoint M _soll ≡ M _{B /} für to be set on the vehicle for the yaw moment variable, wherein due to the consideration of the skew angle difference Δα = α _v -α _h a particularly reliable performance of the vehicle stability ¬ sierenden measures is ensured.

FIG. 2 shows an exemplary embodiment of the method according to the invention in the form of a flow chart. The method is started in an initialization step 20, whereupon, in a first main step 21, the longitudinal velocity variable V ₁ and / or the lateral velocity variable v _q and / or the lateral acceleration variable a _q and / or the float angle variable β and / or the yaw rate ψ and / or the Radlenkwinkelgröße δ and / or the Federweggrö¬ Shen and / or the roll rate and / or the Schwer¬ point size size s _sp and / or the static friction coefficient μ _r ermit¬ telt is. These variables form the input variables of the stability regulator.

In a second main step 22, based on the input variables determined in the preceding first main step 21, the actual value x _{is determined} , the setpoint value x _soll and the limit value x _{limit of} the transverse dynamic quantity are determined.

If it is determined in a third main step 23 that the determined desired value x _{soll of} the transverse dynamic quantity is the determined limit value x _! in terms of amount,

I Xsoll I> I Xlimit \, (4.1)

then in a fourth main step 24, the value determined is Soll¬ x ^χ _so ii lateral dynamics variable to the determined limit _cross limited. Subsequently, a fifth main step 25 is continued.

If, on the other hand, it is recognized in the third main step 23 that the condition given by the equation (4.1) is not met, the method continues directly with the fifth main step 25.

In the fifth main step 25 is a function of the method equalization _is x between the determined actual value and the ermit¬ telten and begrenz¬ th optionally in a fourth main step 24, target value x _so the transverse dynamics of size n of the set value M to be set to increase the driving stability of the vehicle _{is to} the Yaw momentum determined, whereupon in a sixth Haupt¬ step 26, the longitudinal and / or lateral dynamics of the vehicle der¬ art is affected, that adjusts the determined setpoint M _so ii corresponding actual value M _is the yaw momentum on Fahr¬ zeug. In this case, a braking torque and / or braking force request present on the driver side is taken into account. This results from the deflection m caused by the driver on the brake control element 13, which is provided in a first secondary step 31.

Subsequently, the method is terminated in a final step 27.

Claims

claims

1. A device for stabilizing a vehicle, with a detection device (10), which is provided for determining an Ist¬ value (Xi _st ) of the transverse dynamics of the vehicle be¬ writing transverse dynamics variable, and with ei¬ ner evaluation unit (11) having a Reference value (x _so n) determined for the transverse dynamics quantity and limited to a limit value (x _gren z) determined as a function of a given stability condition, if it is found that the desired value (x _so n) of the transverse dynamic quantity exceeds the determined limit value (x _limit ) amount exceeds, wherein the evaluation unit (11) for influencing the longitudinal and / or the transverse dynamics of the vehicle provided Fahrzeugaggre¬ gate (12) as a function of a comparison between the determined actual value (x _is ) and the determined and possibly limited setpoint (x _so ii) controls the Querdynamik¬ size such that the driving stability of Fahr¬ vehicle is increased, characterized in that the di e transverse dynamic quantity is a Kippwinkelgröße (φ), which describes a tilt angle (φ) of the vehicle, and / or a slip angle size (α), which describes a skew angle (α) occurring at a Fahr¬ includes.

2. Apparatus according to claim 1, characterized in that the Kippwinkelgröße (φ) the tilt angle (φ) itself and / or the temporal behavior of the tilt angle (φ) be¬ writes.

3. A device according to claim 1, characterized in that the slip angle size (α) describes the occurring at a Vorder¬ wheel axle of the vehicle slip angle (α _v ) and / or occurring at a rear wheel axle of the vehicle slip angle (α _h ).

4. The device according to claim 1, characterized in that the slip angle size (cc) a skew angle difference (Δα) between the occurring at the front wheel axle of the vehicle slip angle (α _v ) and occurring at the rear wheel axle of the vehicle skew angle (α _h ) describes.

5. The device according to claim 1, characterized in that the evaluation unit (11) as a function of Ver¬ equal between the actual value (x _is ) and the desired value (x _so ii) of the transverse dynamics quantity to be set to increase the Fahr¬ stability on the vehicle setpoint (M _soll ) a Giermomentgrße, which describes a vehicle acting on the yaw moment, determined, wherein the control of the vehicle units (12) then takes place such that the determined setpoint (M ₃₀₁₁ ) corresponding actual value (Mi _st ) set the yaw momentum on the vehicle becomes.

6. The device according to claim 1, characterized in that the vehicle units (12) at least Radbremsein¬ directions (12a ... 12d), which are provided for braking je¬ Weils assigned vehicle wheels, wherein the control of Radbremseinrichtungen (12a ... 12d) to Increasing the driving stability by radselektive specification to be generated braking torque and / or braking forces takes place.

7. The device according to claim 6, characterized in that the evaluation unit (11) in the radselektiven Vor¬ task of the braking torque and / or braking forces to be generated an optionally driver side present Bremsmomen¬ tanforderung and / or braking force request taken into account.

8. The device according to claim 1, characterized in that the evaluation unit (11) the actual value (x _is ) of the transverse dynamics quantity on the basis of an input variable which describes the current state of motion of the vehicle, er¬ mediates.

9. The device according to claim 1, characterized in that the evaluation unit (11) determines the desired value (x _so n) of the transverse dynamic quantity on the basis of an input variable which describes the instantaneous state of motion of the vehicle.

10. The device according to claim 1, characterized in that the limit value (x _grenZ ) of the transverse dynamics quantity is either fixed or determined by the evaluation unit (11) on the basis of an input variable which describes the current state of motion of the vehicle.

11. The device according to at least one of claims 8 to 10, characterized in that it is the input quantity by a Längsgeschwin¬ digkeitsgröße (V ₁ ), the longitudinal velocity of the Vehicle describes, and / or by a Quergeschwindig- keitsgröße, which describes a lateral velocity (v _q ) of the vehicle, and / or by a lateral acceleration quantity (a _q ), which describes a vehicle acting on the Querbe¬ acceleration, and / or by a Schwimmwinkel¬ size (ß), which writes the slip angle of the vehicle be¬, and / or by a yaw rate (ψ), which describes the yaw rate of the vehicle, and / or by a Rad¬ steering angle size (δ), the describes a wheel steering angle set on steerable vehicle wheels, and / or spring travel dimensions (di _{, i = 1.} , ₄ ) describing compression travel occurring on wheel suspension devices of the vehicle, and / or a roll rate variable describing the roll rate of the vehicle; and / or by a center of gravity position (s _sp ) which describes the position of the center of gravity of the vehicle, and / or by a coefficient of static friction (μ _r ) which forms an intermediate vehicle wheels and the road surface Stiction describes, acts.

12. A method for stabilizing a vehicle, in which an actual value (x _is ) of a transverse dynamics of the vehicle be¬ writing transverse dynamics variable is determined, and in which a setpoint (x _so u) determined for the transverse dynamics quantity and to a function of a given Stabili ¬ limited condition limit (x _limit ) is limited, if it is determined that the desired value (x _so u) of the transverse dynamics size exceeds the determined limit value (x _limit ) trag¬, the longitudinal and / or Quer¬ dynamics of the vehicle in Dependence of a comparison between the determined actual value (x _ist ) and the ascertained and possibly limited desired value (x _so n) of the transverse dynamics variable is influenced in such a way that the driving stability of the vehicle is increased, characterized in that the transverse dynamic quantity is a tilting angle variable ( φ), which describes a tilt angle (φ) of the vehicle, and / or a slip angle size (α), which is a n at a driving zeugrad occurring slip angle (α) describes urafasst.